Quote:
Originally Posted by
otheus
It seems like you don't have a real problem, and that you were asking a theoretical question -- like fact-checking GeekSqaud personnel.
I'm currently eating all of my memory and would like to get the last half-gig. What's more, I'd like to know if I'd be able to double the memory further (buying 4x2GB, since my current setup is full at 4x1GB). So no, it's not theoretical.
Quote:
Originally Posted by
otheus
Do you or do you know what's eating your top in .5 GB of memory?
I don't understand why we don't understand each other on this point. I have a 64-bit processor and a 64-bit operating system; I should have no trouble addressing 128 GB. Video memory only reduces currently-available memory if you've used up your addressing limit. So when I had 2 GB and was uncontroversially below my addressing limit, I could see all 2 GB (precisely 2048 MB). Video mapping did not reduce the memory at all.
But now 512 MB are not showing up. The possibilities, as I see them:
1. The OS can only address 32 bits, so only 3.5 GB can be used.
2. The processor can only address 32 bits, so only 3.5 GB can be used.
3. The motherboard can only address 32 bits, so only 3.5 GB can be used.
4. The BIOS is misconfigured to address only 32 bits, so only 3.5 GB can be used.
5. The BIOS is misconfigured in some other way that causes only 3.5 GB to show up.
6. The RAM is bad in some bizarre way that causes only 3.5 GB to be usable.
7. 4 GB are available, but for some reason the tools I'm using (ps, gnome-system-monitor, the BIOS) only see 3.3 to 3.5 GB.
8. Something else is wrong.
#1 and #2 clearly don't apply to me: the OS is 64-bit and the processor, a Phenom II, is also 64-bit. I don't think that #4 is possible. I've looked through the BIOS settings pretty carefully and didn't see anything, but I concede that #5 is possible. #6 and #7 seem absurd. #8 is always a possibility.
What do you think?
Quote:
Originally Posted by
otheus
Can you check if it's the video?
I know of no way to do this.
Quote:
Originally Posted by
otheus
A 32-bit processor can natively and directly address 4 GB of memory. Since the 8086 architecture allowed for a "segment" address combined with an actual memory pointer, the x86 architecture theoretically maintains the ability to address more memory than this.
As I have an x86_64 (aka AMD64) processor rather than the classic x86, I don't think this is particularly relevant. Of course the microarchitecture is similar, but I don't think there's any disagreement as to the chip's ability to work with more than (say) 8 GB of memory.
Quote:
Originally Posted by
otheus
I doubt it hard to believe that a 64-bit chip would be able to address more memory.
I don't follow...?